The objective of this study is to develop a technology to culture the cells of the lung that are important in the maintenance of normal parenchymal structure in health disease. Using physical enzymatic, and biological methods of isolation and culturing of lung cells, several cell strains have been developed including: fibroblasts from normal adult human lung, adult human lung from patients with a variety of lung disorders, fetal human lung, newborn rabbit lung, fetal rabbit lung, newborn rat lung, fetal cat lung, and adult rabbit skin. In addition, epithelial cells have been isolated from fetal cat lung and alveolar Type II cells have been isolated from the adult rabbit lung. Studies with some of these cells have demonstrated that lung fibroblasts maintain their differentiated state over many subcultivations. While fetal skin and lung fibroblasts are almost identical, they appear to differentiate with development so that they are quite different in the adult life. Cell synchrony studies suggest that human fetal lung fibroblasts have an S phase of approximately 7 to 10 hours, A G1 phase of 10 to 12 hours and a G2 phase of approximately 3 hours. With these techniques, it should be possible to utilize sophisticated biochemical methodologies to evaluate the status of lung cell in human pulmonary disorders. BIBLIOGRAPHIC REFERENCES: Horwitz, A.L., Hance, A.J.,and Crystal, R.G. Granulocyte Collagenase: Selective Digestion of Type I over Type III Collagen. Proc. Nat. Acad. Sci., 1977, 74, 897-901, 1977. Hance, A.J. and Crystal, R.G. Rigid Control of the Synthesis of Collagen Types I and III by Cells in Culture. Nature, 268, 152-154, 1977.